What should I do if the win10 installation fails?

What should I do if the win10 installation fails? The next small series for users to bring the Win10 installation technology preview version of the system Q & A and notes, you can see if the following requirements are met, in order to find out the reasons for the installation failure, you can also refer to the small series win10 installation tutorial The full version is reinstalled.
Please download and install this preview only when the following conditions are met
• I hope to try out the software that is still under development and I would like to share my views and opinions about the software.
• Know how to back up your computer, format your hard drive, and install the operating system from scratch.
• Learn how to restore your previous operating system (if necessary).
• Really understand the computer, you can easily solve the computer problem.
• Don't mind having a lot of updates or major changes to the UI design after a while.
• Do not install this software on a computer that you use every day.
Remember, this software is still under development and may have certain risks. That's why we recommend that you do not install the software on major home or business computers. You should also back up everything, as the following are likely to happen:
• Unexpected computer crashes and file loss.
• Unable to install or not function properly, including anti-virus or security programs.
• Printers, video cards, or other hardware do not work.
• Access to a company or home network is difficult.
• Corrupt some files.
System Requirements
Basically, if your computer can run win8.1, you can safely start the installation. If you are not sure, don't worry about — Windows will check your system to make sure you can install Win10 Technology Preview.
• Processor: 1 gigahertz (GHz) or faster
• Memory: 1 GB (32 bit) or 2 GB (64 bit)
• Available hard disk space: 16 GB
• Graphics Card: Microsoft DirectX 9 Graphics Device with WDDM Driver
• Microsoft Account and Internet Access
Language
Technology Preview is available in English, Chinese (Simplified) and Brazilian Portuguese .
Compatibility
Technology Preview should be for devices and programs that work with Windows 8.1, but some devices and programs may need to be updated or reinstalled.
Windows drivers for basic functions such as storage, networking, input and display. These drivers let you complete Windows installation and connect to the Internet. More drivers are available from Windows Update.
Note
If you are running Windows 8.1, win8 or win7, and the system language is not English, Chinese (Simplified) and Brazilian Portuguese, you can only keep personal files during the upgrade. You will not be able to keep your app or Windows settings.
If you are running Windows 8.1, Windows 8, or Windows 7, and a language pack or language interface pack (LIP) is installed, it will be removed when you install the Technology Preview.